The sternum or the chest bone is a long flat bone located in the center of the thorax and the costal cartilages are the cartilages that connect the chest bone with the ends of the ribs. Pectus excavatum is referred to the condition where the sternum and costal cartilages are deformed resulting in a horizontal narrowing of the chest primarily on the posterior side. The middle of the chest appears to be flat or concave rather than slightly convex. Brachycephalic (short-nose) breed dogs are predisposed to this condition and in most cases are born with (congenital) this disability.
Common symptoms include
Unable to perform routine exercise
Increased depth of breathing
Recurrent lung infections
Failure to gain weight